A self-engaging emergency egress lock assembly mounted to a door track is described. As a door lock strike element contacts a lock strike assembly contained within the door lock assembly, the strike assembly hinges over the door lock strike element. When the door reaches a predetermined down limit power is applied to activate an actuator. Upon activation, the actuator engages a lock strike stop which prevent the strike assembly from disengaging the door lock strike element. If the door is attempted to be opened while the lock strike stop is engaged, the lock strike assembly pushes against the stop, preventing the door from traveling upward. In an emergency egress (alarm) condition, power to the actuator is terminated, thereby releasing the lock strike stop and by extension, the strike assembly, thus disengaging the door lock strike element, thereby providing emergency egress capability.